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Florida Arbovirus Surveillance Week 30: July 19-25, 2020

Arbovirus surveillance in Florida includes endemic mosquito-borne viruses such as West Nile virus (WNV), Eastern equine encephalitis virus (EEEV), and St. Louis encephalitis virus (SLEV), as well as exotic viruses such as dengue virus (DENV), chikungunya virus (CHIKV), Zika virus (ZIKV), and California encephalitis group viruses (CEV). Malaria, a parasitic mosquito-borne disease is also included. During the period of July 19-25, 2020, the following arboviral activity was recorded in Florida. WNV activity: Three human cases of WNV infection were reported this week. No horses with WNV infection were reported this week. One sentinel chicken tested positive for antibodies to WNV this week in Citrus County. Three mosquito pools tested positive for WNV this week in Miami-Dade County. In 2020, positive samples from three humans, 22 asymptomatic blood donors, one horse, three crows, six blue jays, 12 mosquito pools, and 36 sentinel chickens have been reported from 11 counties. SLEV activity: No human cases of SLEV infection were reported this week. No sentinel chickens tested positive for antibodies to SLEV this week. In 2020, no positive samples have been reported. EEEV activity: No human cases of EEEV infection were reported this week. Three horses with EEEV infection were reported this week in Bradford, Clay, and Santa Rosa counties. No sentinel chickens tested positive for antibodies to EEEV this week. In 2020, positive samples from 17 sentinel chickens, 15 horses, one duck, and one mosquito pool have been reported from 14 counties. International Travel-Associated Dengue Fever Cases: No cases of dengue fever were reported this week in persons that had international travel. In 2020, 29 travel-associated cases have been reported. Dengue Fever Cases Acquired in Florida: Five cases of locally acquired dengue fever were reported this week. In 2020, 22 cases of locally acquired dengue fever have been reported. International Travel-Associated Chikungunya Fever Cases: No cases of chikungunya fever were reported this week in persons that had international travel. In 2020, no travel-associated chikungunya fever cases have been reported. Chikungunya Fever Cases Acquired in Florida: No cases of locally acquired chikungunya fever were reported this week. In 2020, no cases of locally acquired chikungunya fever have been reported. International Travel-Associated Zika Fever Cases: No cases of Zika fever were reported this week in persons that had international travel. In 2020, no travel-associated Zika fever cases have been reported. Zika Fever Cases Acquired in Florida: No cases of locally acquired Zika fever were reported this week. In 2020, no cases of locally acquired Zika fever have been reported. Advisories/Alerts: Holmes and Palm Beach counties are currently under a mosquito-borne illness advisory. Miami-Dade and Monroe counties are currently under a mosquito-borne illness alert. No other counties are currently under mosquito-borne illness advisory or alert. There is a Level 2 Travel Health Notice for Nigeria related to the transmission of yellow fever virus. A Level 1 Travel Health Notice has been issued for Ethiopia related to the transmission of yellow fever and chikungunya viruses. There are also Level 1 Travel Health Notices for Central and South America, Mexico, the Caribbean, Asia, the Pacific Islands, Africa, and the Middle East related to the transmission of dengue virus, and for

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Burundi related to malaria transmission. Additional information on travel health notices can be found at the following link: wwwnc.cdc.gov/travel/notices. For a map of arboviral disease activity in the United States visit: wwwn.cdc.gov/arbonet/maps/ADB_Diseases_Map/index.html.

2020 Human Case Summary*

West Nile Virus Illnesses Acquired in Florida: Three human cases of WNV illness acquired in Florida have been reported in 2020: two in Miami-Dade County (June) and one in Palm Beach County (July). Twenty-two asymptomatic positive blood donors have been reported in 2020 from Miami-Dade County (May, June, and July). International Travel-Associated Dengue Fever Cases: Twenty-nine cases of dengue fever with onset in 2020 have been reported in individuals with travel history to a dengue endemic area in the two weeks prior to onset. Counties reporting cases were: Brevard, Broward (5), Clay, Collier, Duval, Franklin, Hillsborough (3), Miami-Dade (11), Orange, Palm Beach, Sarasota, Seminole, and St. Lucie. Four cases were reported in non-Florida residents. In 2020, 20 cases of dengue reported in Florida have been serotyped by PCR. Please see the table below for a breakdown of cases by country of origin and serotype.

Dengue Fever Cases Acquired in Florida: In 2020, 22 cases of locally acquired dengue fever have been reported in Miami-Dade and Monroe (21) counties, with onsets in February, March, June, and July. One case was reported in a non-Florida resident. International Travel-Associated Malaria Cases: Nine cases of malaria with onset in 2020 have been reported. Countries of origin were: Cameroon, Dominican Republic, Kenya (2), Nicaragua, Nigeria, Sierra Leone, Uganda, and Venezuela. Counties reporting cases were: Broward (3), Miami-Dade (2), Orange, Osceola, Palm Beach, and Polk. Two cases were reported in non-Florida residents. Five cases (56%) were diagnosed with Plasmodium falciparum. Two cases (22%) were diagnosed with Plasmodium vivax. One case (11%) was diagnosed with Plasmodium ovale. The Plasmodium species for one case (11%) was unknown due to low parasitemia.

Country of Exposure DENV-1 DENV-2 DENV-3 DENV-4 DENV-1/ DENV-3

Unknown Total

Cuba 2 1 1 4

Jamaica 3 1 4

Bolivia 2 2 4

Colombia 2 2

Dominican Republic 2 2

Indonesia 2 2

Antigua and Barbuda 1 1

Bahamas 1 1

Brazil 1 1

Mexico 1 1

Nicaragua 1 1

Paraguay 2 2

Puerto Rico 2 2

Puerto Rico/US Virgin Islands 1 1

US Virgin Islands 1 1

Total 10 3 4 2 1 9 29

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Veterinary Cases*

*Veterinary cases are reported by date of onset. Only mammalian veterinary cases are included in the graphs.

Three horses with EEEV infection were reported this week in Bradford, Clay, and Santa Rosa counties.

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Sentinel Chickens*

The table below is for the reporting of confirmatory laboratory results from this week. Some of the samples were collected at earlier dates. The date of collection is recorded for samples collected on that day along with the total number of positives and the corresponding seroconversion rate for the week the sample was collected. One sentinel chicken tested positive for antibodies to WNV this week in Citrus County.

Seroconversion Rates (%) County Totals

County Collection

Date Flavi SLEV WNV Alpha EEEV HJV

Collection Week

YTD

Citrus 7/14/2020 1.28 1.28 1 WNV 9 WNV, 2 EEEV

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Mosquito Pools

Three mosquito pools tested positive for WNV this week in Miami-Dade County.

County Collection Date

Result Species County YTD

Miami-Dade 7/14/2020 7/14/2020

2 WNV 1 WNV

Cx. quinquefasciatus Cx. nigripalpus

12 WNV

Dead Birds

The Fish and Wildlife Conservation Commission (FWC) collects reports of dead birds, which can be an indication of arbovirus circulation in an area. This week, nine reports representing a total of 32 dead birds, including one crow, two raptors, and seven doves, were received from seven counties. In 2020, 254 reports representing a total of 649 dead birds (40 crows, 34 jays, 66 raptors, 32 doves) were received from 40 of Florida’s 67 counties. 2020

Maps

County Total Dead Birds Crows Jays Raptors Doves

Alachua Collier Miami-Dade Orange Pasco Pinellas Polk

1 5 5 1 1 18 1

0 0 0 1 0 0 0

0 0 0 0 0 0 0

1 0 0 0 0 0 1

0 5 1 0 0 1 0

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2020 Arbovirus Activity by County

County Arbovirus Activity

Baker EEEV: 2 horses (6/17, 7/5), 1 bird (5/7)

Bradford EEEV: 1 horse (7/18)

Brevard WNV: 2 sentinels (1/23, 1/24)

Citrus WNV: 9 sentinels (1/8, 1/14, 1/21, 7/14) EEEV: 2 sentinels (1/8, 3/2)

Clay EEEV: 1 horse (7/11)

Gilchrist EEEV: 1 horse (7/6)

Hernando EEEV: 1 sentinel (1/21)

Hillsborough WNV: 12 sentinels (1/6, 1/21, 1/29, 2/11, 2/18, 2/25)

Holmes WNV: 1 horse (6/7) EEEV: 4 horses (6/3, 6/7, 6/9, 7/13)

Indian River WNV: 3 sentinels (1/2, 1/9, 1/10)

Jackson EEEV: 2 horses (6/27, 7/13)

Manatee WNV: 3 sentinels (1/8)

Miami-Dade

WNV: 2 humans (June), 22 asymptomatic blood donors (May, June, July), 9 birds (5/20, 6/18, 6/24, 6/25, 6/26), 12 mosquito pools (6/9, 6/16, 6/23, 6/30, 7/14) EEEV: 1 mosquito pool (1/7) Dengue: 1 human (March)

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Monroe Dengue: 21 humans (February, June, July)

Orange WNV: 3 sentinels (1/6) EEEV: 1 horse (3/25), 8 sentinels (1/13, 1/27, 1/28, 2/24, 3/2)

Palm Beach WNV: 1 human (July), 1 sentinel (1/20)

Pasco WNV: 2 sentinels (1/7)

Polk EEEV: 1 horse (3/29)

Santa Rosa EEEV: 1 horse (7/20)

Volusia WNV: 1 sentinel (5/4) EEEV: 1 horse (1/24), 4 sentinels (2/24, 3/30, 5/18)

Walton EEEV: 2 sentinels (6/22, 7/6)

Acknowledgements and Data Sources

Contributors: Andrea Morrison, PhD, MSPH, Devin Rowe, MS, Catherine McDermott, MPH, MHS, and Danielle Stanek, DVM, DOH Bureau of Epidemiology; Lea Heberlein-Larson, DrPH; Alexis LaCrue, PhD, MS; Maribel Castaneda, and Valerie Mock, BS; DOH Bureau of Public Health Laboratories; Carina Blackmore, DVM, PhD, DOH Division of Disease Control and Health Protection.

For more surveillance information, please see the DOH website at: www.floridahealth.gov/diseases-and-conditions/mosquito-borne-diseases/surveillance.html For arbovirus surveillance information for the United States, please see the Centers for Disease Control and Prevention website at: www.cdc.gov/ncidod/dvbid/westnile/surv&control.htm Case tallies included in the weekly Florida arbovirus surveillance report include confirmed and probable cases for EEE, WNV infection, SLE, dengue, chikungunya, and malaria by date of onset. Suspect cases are not included. Activity is mapped by county of exposure rather than county of residence. Case definitions being used in Florida are consistent with national criteria provided by the Council of State and Territorial Epidemiologists (CSTE) and may be viewed at: www.floridahealth.gov/diseases-and-conditions/disease-reporting-and-management/disease-reporting-and-surveillance/index.html. Case tallies reported by CDC do not include suspect cases and cases are reported by patient state of residence rather than where the exposure occurred. Data is provided by county health departments, Department of Health Bureau of Public Health Laboratories, Department of Agriculture and Consumer Services, mosquito control agencies, Florida Fish and Wildlife Conservation Commission, medical providers and veterinarians. Equine cases are provided by the Department of Agriculture and Consumer Services.